Multiple contact electromagnetically actuated switch and accessories therefor



Nov. 21, 1967 .1. J. GRIBBLE ET AL 3,354,415

MULTIPLE CONTACT ELECTROMAGNETICALLY ACTUATED SWITCH AND ACCESSORIES THEREFOR Filed July 20,. 1965 10 Sheets-Sheet 1 INVENTOR.

JOSEPH J. GR/BBLE 1 BY KENNETH 1 MAR/EN HAROLD E. WH/T/NG Nov. 21, 1967 J. J. GRIVBBLE ET AL I 3,354,415

MULTIPLE CONTACT ELECTROMAGNETICALLY ACTUATED' SWITCH AND ACCESSORIES THEREFOR l0 Sheets-Sheet Filed July 20, 1965 B O 2 Z START STOP INVENTOR.

JOSEPH J. GR/BBLE KENNETH JMAR/EN HAROLD E. WH/T/NG 452 5- 5 WM ww Nov. 21, 1967 J. J. GRIBBLE ET AL 3,354,415

MULTIPLE CONTACT ELECTROMAGNETICALLY ACTUATED SWITCH AND ACCESSORIES THEREFOR Filed July 20, 1965 10 Sheets-Sheet 5 r I 935 2a0 95 94c r93? INVENTOR.

3 JOSEPH J. GR/BBLE BY KENNETH J. MAR/EN HAROLD E. WH/T/NG Nov. 21, 1967 J. J. GRIBBLE ET AL 3,354,415

MULTIPLE CONTACT ELECTROMAGNETICALLY ACTUATED SWITCH AND ACCESSORIES THEREFOR l0 Sheets-Sheet 4 Filed July 20, 1965 E G in IT mmmm m G M w v 1 m 5 Hmo PEL E.N0 T E 1 J K H v 3 2 Y B 7 2 3,354,415 MULTIPLE CONTACT ELECTROMAGNETICALLY ACTUATED SWITCH Nov. 21, 1967 .1. J. GRIBBLE ET AL AND ACCESSORIES THEREFOR l0 Sheets-Sheet 6 Filed July 20, 1965 FIG. 8

INVENTOR.

JOSEPH J. GR/BBLE G N m M A W 15 mu m we EA K H Y B Nov. 21, 1967 .1. .1. GRIBBLE ET AL 3,354,415

MULTIPLE CONTACT ELECTROMAGNETICALLY ACTUATED swrrcn AND ACCESSORIES THEREFOR Filed July 20, 1965 10 Sheets-Sheet 7 INVENTOR, QTOSEPH J- GRlBB BY KENNETH J: MAR/EN HAROLD E. WH/T/NG F/Ell Nov. 21, 1967 J. J. GRIBBLE ET AL 3,354,415

, MULTIPLE CONTACT ELECTROMAGNETICALLY ACTUATED SWITCH AND ACCESSORIES THEREFOR Filed July 20, 1965 10 Sheets-Sheet 8 INVENTOR.

JOSEPH J: .GRIBBLE BY KENNETH .JiMAR/EN HAROLD E. WH/T/NG 3,354,415 MULTIPLE CONTACT ELECTROMAGNETICALLY ACTUATED SWITCH Nov. 21, 1967 J. J. GRIBBLE ET AL AND ACCESSORIES THEREFOR Filed July 20, 1965 10 Sheets-Sheet 9 F/El4' INVENTOR. JOSEPH J- GRIBBLE BY KENNETH J MAR/EN HAROLD United States Patent 3,354,415 MULTIPLE CONTACT ELECTROMAGNETI- CALLY ACTUATED SWITCH AND ACCES- SGRIES THEREFQR Joseph J. Gribble, Kenneth J. Marien, and Harold E.

Whiting, Milwaukee, Wis., assignors to Square D Company, Park Ridge, llL, a corporation of Michigan Filed July 20, 1965, 'Ser. No. 473,299 23 Claims. (Cl. 335-431) ABSTRACT OF THE DISCLOSURE A multiple contact electromagnetically actuated contactor having a bell crank connection between a magnet armature and a movable contact carrier so the armature moves in a path of travel parallel to a mounting panel and the movable contacts in a path perpendicular to the panel to minimize contact bounce and an arrangement whereby the magnet coil and contacts each are enclosed in separate detachable housings to permit servicing and replacement without disturbing the wire connections to the stationary contacts and an arrangement whereby a pair of contactors may be mounted side by side on a support which positions a mechanical interlock between the contactors and the mounting panel to minimize the mounting area required by the interlocked contactors and to provide the contactors with openings in their bottom and side walls to actuate the mechanical interlocks and externally operated switches which may have rotary or linearly movable actuators when the switches are mounted on either side of the contactors.

The present invention relates to electromagnetic switching devices and more particularly to electromagnetic contactors and to switching assemblies which may be combined therewith.

Electromagnetic switching devices of the type with which the present invention is concerned are commonly known as contactors, which, in industrial control environments, may be used individually or in combination with other switching units and may be mounted as exposed on a control panel or within an enclosure. From the standpoint of application, contactors may be regarded as basic switching units as they are frequently com-. bined with other switching units and mechanical interlocking mechanisms to perform a great variety of circuit control functions. Among the prime considerations which an industrial type contactor is required to satisfy is that the contactor must occupy a minimum space on a panel and have a minimum weight for a given voltage and ampere rating. It is one of the objects of the present invention to satisfy this requirement.

Additionally, another requirement which an industrial type contactor must satisfy is that it must provide dependable operation throughout a long life when operating at its rated capacity and it must be arranged so it can be easily mounted on a panel and electrical connections can be easily made to both the terminals of the switching assembly and to the terminals of its energizing coil. It is an object of our invention to satisfy all of these requirements.

Other desirable features which are required to be present in an industrial type contactor are that the contactor must be easy to assemble, inspect and replace the various components such as the circuit controlling contacts and coil and be combined with to actuate and support auxiliary switching devices, mechanical interlock devices and an indicating device, such as a pilot light, as well as support auxiliary electrical devices such as overload relays, and manually actuated switches. It is ice an object of our invention to satisfy all of these requirements.

Heretofore, in attempting to satisfy the foregoing requirements, contactors known as vertical acting contactors have been furnished which included an arrangement wherein the movable elements of the electromagnet and the movable contacts of the contactor moved along axes in parallel vertical planes so that the shock which occurred when the moving heavy magnetic metal parts of the electromagnet are stopped in their fully energized position caused an undesirable vibration of the movable contacts of the contactor. This undesirable result is known as contact bounce.

This arrangement was objectionable in that it required the incoming and outgoing conductor wires to be attached at the top of the contactor providing an undesirable wire arrangement which was further complicated when an overload relay was positioned at the bottom side of the basic contactor to form a device commonly known as a starter.

In an effort to solve the wiring difi'iculties, contactors known as horizontal acting contactors have been furnished which were arranged so the movable contacts and movable electromagnet parts moved in a plane perpendicular to the panel on which the contactor is mounted. While this arrangement provided a solution to the wiring problem in that it permitted the incoming conductors to be connected at one side of the contactor, e.g., the top of the contactor, and the outgoing conductors to be connected at the other, or bottom side of the contactor, it did not diminish the contact bounce problem.

Recognizing the deficiencies as above described in contactors, wherein the movable electromagnet parts and the movable contacts moved along the same axis, contactors have been provided which included an arrangement wherein the movable contacts moved along an axis perpendicular to the panel on which the contactor is mounted while the movable parts of the electromagnet moved along an axis parallel to the panel on which the contactor is mounted. While the contactors, which were arranged so the movable contacts and the movable electromagnet parts moved along axes which were mutually perpendicular, did minimize the problem of contact bounce and simplified the problem of connecting the incoming and outgoing conductors to the device, the arrangements which were heretofore tried increased the difficulties of combining the basic contactor with auxiliary switches and mechanical interlock structures without imposing unbalancing forces on the movable contact structure or the electromagnet structure which greatly decreased the durability and reliability of the contactor.

Accordingly, it is another object of our invention to provide an electromagnetic switching device, commonly known as a contactor, which is arranged so the movable contacts of the contactor move along an axis perpendicular to a mounting panel while the movable parts of the electromagnet move along an axis which is parallel to the panel and to transmit the movement of the movable parts of the electromagnet to the movable contacts through a unitary lever which is pivotally mounted on two widely spaced bearings and pivotally connected to a support for the movable contacts through two widely spaced bearings.

A still further object is to provide a contactor in which both the movable and stationary contact portions of the switching contacts are substantially total enclosed but may be easily inspected and replaced by a simple disassembly operation of one portion of the contactor apparatus from another portion without disturbing the connections of any of the wires connected to and from the contactor.

Another object is to provide a contactor in which both the movable and stationary contact portions of the switching contacts are substantially totally enclosed but may be easily inspected and replaced by a simple disassembly operation of one portion of the contactor from another and in which the electromagnet which is also substantially totally enclosed may be easily inspected and replaced by a simple disassembly operation of a cover for the contactor from the said another portion without disturbing the connections of any of the wires connected in circuit with the switching contacts.

A further object is to provide a contactor with a base which has a pair of spaced stationary contacts in each of a plurality of compartments, a housing mountable on the base enclosing an electromagnet and providing a guide for a carrier which is arranged to position a plurality of movable contacts so the movable contacts engage the stationary contacts when the carrier is moved by the electromagnet toward the base and to resiliently position an electrical switch in either of two additional compartments in the base which are located adjacent the outer walls of the base so an actuator for the switch is moved by the carrier upon movement of the carrier by the electromagnet.

A further object is to provide a contactor with a base which has a pair of spaced stationary contacts in each of a plurality of compartments, a housing mountable on the base enclosing an electromagnet which provides a guide for a carrier which is arranged to position a plurality of movable contacts so the movable contacts will engage the stationary contacts when the carrier is moved by the electromagnet toward the base, to include an electrical switch in either of two compartments in the base which are located adjacent the outer walls of the base so an actuator for the switch is moved by the carrier upon movement of the carrier by the electromagnet and to provide the actuator with a stepped cam portion for actuating a movable contact of the switch which cam is arranged so vibrations of the carrier are isolated from the movable contact.

A further object is to provide a contactor with a base which has a pair of spaced stationary contacts in each of a plurality of compartments, a housing mountable on the base enclosing an electromagnet which provides a guide for a carrier which is arranged to position a plurality of movable contacts so the movable contacts engage the stationary contacts when the carrier is moved by the electromagnet toward the base to include an electrical switch in either of two compartments in the base which are located adjacent the outer walls of the base so an actuator for the switch is moved by the carrier upon movement of the carrier by the electromagnet and to provide the actuator with a stepped cam portion for actuating a movable contact of the switch which cam is arranged so vibrations of the carrier are isolated from the movable contact.

An additional object is to position a pair of contactors in spaced relation on a common U-shaped channel member and to provide a mechanical interlock mechanism for preventing simultaneous movement of the parts of both contactors to an energized position which is received between the arms of the channel member and has a pair of spaced plungers each of which extends through an opening in the base for one of the contactors so as to be movable by a carrier for the movable contacts and to provide an electrical switch in either of two compartments in the base which are located adjacent the outer walls of the base to have an actuator in alignment with the openings in the base so an actuator for the switch is moved by the carrier upon movement of the plunger of the interlock mechanism.

A further object is to provide a contactor with a base which supports a plurality of pairs of stationary contacts and an assembly including a housing, which is detachably carried on the base, which housing is formed to have an internal caivty and a rectangular opening in the bottom wall of the cavity so the U-shaped carrier which has a bight portion carrying movable contacts external to the bottom external surface of the housing and arm portions guided for movement on opposite side walls of the cavity will cause the movable contacts to engage the stationary contacts when the carrier is moved in one direction, resilient means interposed between the bottom wall and the bight portion of the carrier for urging the carrier in a direction opposite said one direction, stop means on the carrier engageable with the bottom external surface of the housing for limiting movement of the carrier in the said opposite direction, a unitary bell crank journalled on bearings at its opposite ends and having a pair of spaced arms pivotally mounted in the arm portions of the carrier and arm pivotally connected with an armature of a magnet motor which is positioned in the cavity and a cover for the housing which encloses the cavity and supplies a stressing force on a spring mount for a stationary magnet part of the electromagnet when the cover is secured to the housing.

An additional object is to provide an electromagnetic switching device with a removable movable contact assembly which is engageable with contact portions of a pair of spaced stationary contact assemblies which movable contact assembly includes a spring, a contact unit which is removable from the assembly and a retainer for the contact unit and which assembly is positioned in an opening in a support so the retainer which has a portion received in the opening arranged to be guided by extending ears which engage portion of the support external of the opening is constantly biased by the spring toward a bottom wall of the opening and to provide cooperating lugs and detents on the retainer and contact unit for maintaining the contact unit in said opening between the retainer and the bottom Wall of the opening.

An additional object is to provide an electromagnetic switching device with a removable movable contact assembly which is engageable with contact portions of a pair of spaced stationary contact assemblies which movable contact assembly includes a spring, a contact unit which is removable from the assembly and a retainer for the contact unit and which assembly is positioned in an opening in a support so the retainer which has a portion received in the Opening arranged to be guided by extend ing ears which engage portion of the support external of the opening is constantly biased by the spring toward a bottom wall of the opening and to provide cooperating lugs and detents on the retainer and contact unit for main taining the contact unit in said opening between the retainer and the bottom wall of the opening and to provide the contact portions of the stationary contacts with suitable ears which are arranged to engage portions of the side walls of a compartment wherein the contact assenr blies are positioned for guiding the contact portions into a proper position relative to a terminal portion of the stationary contact assembly when the contact portion is se cured to the terminal portion.

A further object is to provide a contactor with a rectangular shape to have a power unit containing the elec tromagnet parts of the contactor mounted in front of a base carrying a plurality of pairs of current carrying parts of the contactor and to transmit a vertical movement of the parts of the electromagnet to a horizontal movement of a carrier carrying the movable contacts of the current carrying parts by a single bell crank lever which is pivoted on horizontally aligned widely spaced bearings and to arrange the parts of the contact-or to permit: (1) a pair of contactors when mounted on a U-shaped channel member to be mechanically interlocked by levers carried by the channel; (2) a switching unit which is responsive to-an excess current flow in any one of the current carrying parts and connected in circuit with the coil of the electromagnet to be mounted adjacent the bottom wall of the contactor; (3) a plurality of switches having rotatable actuators to be mounted adjacent either side wall of the contactor which switches may be positioned either side by side or end to end adjacent either or both of the sidewalls; (4) a switch having a horizontally movable actuator to be mounted adjacent either side wall of the contactor; (5) a pilot light assembly to be mounted adjacent the top and front wall edge of the contactor which pilot light assembly includes a wafer-thin coil which is positioned by the coil and stationary magnet parts of the electromagnet and a detachable bulb carrying base which is positioned by a dovetail slot connection on the top wall of the contactor; and (6) a manual switch to be positioned adjacent the bottom and front wall by a resilient bracket which is held in position by openings in the cover for the contactor.

A further object is to provide a contactor with a rectangular shape to have a power unit containing the electromagnet parts of the contactor mounted in front .of a base carrying a plurality of pairs of current carrying parts of the contactor and to transmit a vertical movement of the parts of the electromagnet to a horizontal movement of a carrier carrying the movable contacts of the current carrying parts by a single bell crank lever which is pivoted on horizontally aligned, widely spaced bearings, and to arrange the parts of the contactor to permit: (1) a pair of contactors when mounted on a Ushaped channel member to be mechanically interlocked by levers carried by the channel; (2) a switching unit which is responsive to an excess current flow in any one of the pairs of current carrying parts and connected in circuit with the coil of the electromagnet to be mounted adjacent the bottom wall of the contactor; (3) a plurality of switches having rotatable actuators to be mounted adjacent either side wall of the contactor which switches may be positioned either side by side or end to end adjacent either or both of the sidewalls; (4) a switch having a horizontally movable actuator to be mounted adjacent either side wall of the contactor; (5) a pilot light assembly to be mounted adjacent the top and front wall edge of the contactor which pilot light assembly includes a wafer-thin coil which is positioned by the coil and stationary magnet parts of the electromagnet coil and a detachable bulb carrying base which is positioned by a dovetail slot connection on the top wall of the contactor; (6) a manual switch to be positioned adjacent the bottom and front wall by a resilient bracket which is held in position by openings in the cover for the contactor; (7) a switch having a rotatable actuator to be positioned in either or both of a pair of compartments in the base and to move all of the actuators of the switches and the levers interlocking the two contactors by portions of the yoke which carries the movable contacts.

Further objects and features of the invention will be readily apparent to those skilled in the art from the specification and appended drawings illustrating certain preferred embodiments in which:

FIG. 1 is an exploded view showing in perspective the components of a switching assembly embodying the features of the present invention.

FIG. 2 is a front elevational view of the switching assembly shown in FIG. 1 with broken lines showing as detached, certain of the accessories which may be combined therewith.

FIG. 3 is a view showing in elevation a side of the switching assembly with certain of the accessories assembled and with certain portions of the housing for the switching assembly broken away to illustrate the operative connections between the switching assembly and accessories.

FIG. 4 is a cross-sectional view taken along line 4-4 in FIG. 2 in the direction of the indicating arrows.

FIG. 5 is an exploded view of the switching assembly taken in the direction of the arrows 55 in FIG. 2.

FIG. 6 is a view of a stationary contact assembly taken in the direction of arrow 6 in FIG. 5, with a portion broken away to illustrate constructional details of a stationary contact and with some of the stationary contacts removed from the stationary contact support.

FIG. 7 is a view of a movable contact actuating portion of the device taken in the direction of arrow 7 in FIG. 5, with portions of the actuating mechanism for the device omitted to the right of a vertical centerline.

FIG. 8 is an exploded plan view of the magnet assembly taken in the direction of arrow 8 in FIG. 5.

FIG. 8A is an end plan view of the coil shown in FIG. 8.

' FIG. 9 is a perspective view of a mechanism for actuating the movable contacts of the switching mechanism which view includes a broken-away portion to illustrate details of a bearing structure used in the mechanism.

FIG. 10 is a side elevational view of a pair of switching assemblies mounted on a common support with a portion of the support broken away to illustrate details of a mechanical interlock which operates between the pair of switching assemblies and with one of the devices having portions thereof removed to illustrate constructional details of an electrical interlock switching mechanism which may be used with the switching assembly as well as an arrangement for supporting a manually operable switching mechanism and the details of the engagement between portions of a cover and other components of the switching mechanism according to the present invention,

FIG. 11 shows, as detached, the operating mechanism for an interlock switch mechanism in FIG. 10 so the portions thereof may be more readily identified.

FIG. 12 is an exploded view showing in perspective the components of a switch mechanism which is shown as detached from the right side of the switch mechanism in FIG. 2.

FIG. 13 is a bottom plan view of a mechanical interlock employed in FIG. 10.

FIG. 14 is an exploded view showing in perspective certain components of the mechanical interlock mechanism in FIG. 13.

FIG. 15 is an elevational View taken in the direction of arrow 15 in FIG. 2 showing the switching assembly with a locking attachment replacing a cover for the switching assembly and the connection between the lock ing attachment and switching assembly.

Referring to the drawings, and particularly to FIG. 2, there is shown an electromagnetic switch assembly 20. The switch 20 as shown in FIGS. 1, 2, and 5 has a mounting plate 21 with a pair of openings 22 which are formed in downwardly indented portions 23 formed in opposite edges of the plate 21 for securing the switch assembly 20 to a panel and the like. The plate 21 also includes a plurality of additional openings which will be hereinafter described. A stationary contact base or support 24, shown in FIG. 1, which is preferably formed of a molded material having arc suppressant capabilities, is positioned on the plate 21, as shown in FIG. 4, by a pair of bosses 25, which extend into suitably located openings in the plate 21. The support 24 is secured to the plate 21 by a pair of screws 26, as in FIG. 6, which are located at diametrically opposite corners of the support 24, and extend through suitable passages 26:: in the support 24 into openings which are threaded into a pair of bosses 27 in the plate 21, as shown in FIG. 5.

As shown in FIG. 6, the construction of the portion of the support 24 to the left of a vertical centerline 20a and above a horizontal centerline 20b is identical and a reverse image of the construction of a portion of the support 24 to the right of centerline 20a and below the centerline 20b. Similarly, the construction of the portion of the support 24 to the right of the centerline 20a and above the centerline 20b is identical and the reverse image of the portion of the support 24 to the left of the centerline 20a and below the centerline 20b. Therefore a description of the parts of the support 24 to the right of the centerline 20a will fully describe the constructional details of the entire support 24.

As shown in FIGS. 1 and 6, the support 24 is provided with a pair of outer walls 28 and partitions 29a, 29b, 30 and 31, which are spaced between and extend parallel to the walls 28 and upwardly from a base or bottom wall 24a of the support 24, as shown in FIG. 4. The walls 28 and the partitions 29a and 2% provide a pair of compartments 32 each of which are closed at an end 33 to provide material for a counterbore around the passages 26a for one of the screws 26. The counterbores of the passages for the screws 26 are sized so the head of the screw 26 is below the upper surface of the support 24 when the support 24 is secured to the plate 21. The material of the support 24 which provides the closed ends 33 of the compartments 32 is formed to extend upwardly above a surface 34, wherein the counterbore for the passages for the screws 26 are formed, as in FIG. 5, to provide a pair of raised bosses 35, as in FIGS. 1, and 6, wherein threaded inserts 36 are embedded. Extending upwardly, as in FIG. 6, through the bottom wall 24a of the support 24 into the compartments 32, are rectangular openings 37 which are centered on opposite sides of the centerline 2611 as shown in FIG. 6, and are aligned with circular openings 370 in the mounting plate 21. The end of the compartments 32 adjacent the opening 37 is provided with an upstanding wall 38 and the end remote from the opening 37 is provided with an upstanding wall 39. As most clearly shown in FIG. 6-, the side wall of the partitions 29a and 29b facing each of the compartments 32 has a vertically extending recess 40 which extends from the top surface of the partitions to the bottom wall 24a of the support 24.

The partitions 30 and 31 are spaced between the walls 29a and 23b to provide three compartments 4-1, 42 and 43, which are of equal width and which extend transverseiy across the entire width of the support 24. As the shape of the bottom wall of each of the compartments 41-43 is identical, only the details of the compartment 42, as shown in FIG. 4, will be specifically described. Further, because the shape of the bottom Wall of the compartment 42 above and below the centerline 20b of the support 24 are identical, only the shape of the bottom wall of compartment 42 above the centerline 26b will be specifically described, reference being had to FIGS. 4 and 6. Spaced above the centerline 20b is an upwardly extending boss 45 which has a top surface 45a inclined toward a recess 46. The reces 46 is formed betwen the boss 45 and a ledge 47 which is terminated by an upwardly curved wall 48. Secured in the material which forms the ledge 47 is a threaded insert 49 which has a portion extending above the upper surface of the ledge 47.

A description of the configuration of the walls which form compartments 41-43 will now be set forth. The shape of the walls of the partitions 29a and 29b which face the compartments 41 and 43 are identical. Similarly, the shape of the walls of partitions 30 and 31 which face compartment 42 are identical. Also the shape of the walls of the partitions 30 and 31 which respectively face the compartments 41 and 43 are identical and, with minor exceptions, the shape of the walls of the partitions 29b and 31 which face compartment 43 are identical. Thus a description of the opposite side walls which form the partition 31 will provide a description of the shape of the walls which form each of the compartments 41-43. Further, as the portions of the partition 31 above and below the horizontal centerline 20b in FIG. 6 are identical in shape, a description of the shape of the wall portion of the partition 31 above the centerline 20b will adequately describe the shape of the walls of the partitions 29a, 29b, 31 and 31 of the support 24.

Extending on opposite sides of the partition 31 are portions 51 and 51 which are spaced to provide a groove 52 which is most clearly seen in FIGS. 4 and 6. The portions 50 have a width as shown in FIG. 6 and as shown in FIG. 4, the portions 51 have an inclined edge 53 forming an entry into groove 52.

As shown in FIG. 1, each of the partitions 29a, 29b, 30 and 31, as well as the end walls 28, are provided with a notch, each of which is of equal width and centered on the centerline 20b. The base 54a of a notch 54 in the walls 28 is shown in FIG. 5. Similarly, the base 55a of a notch 55 in the partitions 29a and 29b is shown in FIG. 5 and the base 56a of the notch 56 in the partitions 30 and 31 is also shown in FIG. 5. As shown in FIG. 6, the walls of the partitions 3t) and 31 facing the compartment 42 are provided with a recess 57 which extends on opposite sides of the centerline 20b. The recesses '57 each have a bottom surface substantially planar with the base 56a of the notches 56. The notches 55 are provided with stepped portions to provide a vertical wall 53 shown in FIG. 6 which stepped portions have a horizontal bot-' tom wall planar with the bases 56a of the notches 56.

The foregoing constitutes a description of the molded insulating support 24.

Securable in each of the compartments 41, 42 and 43 are cooperating pairs of terminal and stationary contact assemblies 60 which are most clearly seen in FIGS. 1, 4 and 6. As each of the assemblies are identical and each are identically positioned in the opposite ends of the compartments 41-43, only the assembly shown to the right in FIG. 4 will be specifically described, it being understood that each of the compartments 41-43 has a stationary contact assembly positioned in opposite directions from its opposite ends at equal distances from the centerline 2019.

As shown in FIG. 4, the stationary contact assembly 60 includes a Z-shaped terminal connector 61 and a removable stationary contact 62. The terminal connector has an upper horizontal portion 63 which rests upon the raised portions 51) and has a threaded opening to receive a screw 65 for tightening a clamp 65a upon a bared end of a wire lead which is not shown. The upper horizontal portion 63 is connected to a lower horizontal portion 67 by an inclined center portion 68. The inclined portion 68 is provided with a threaded opening to receive a screw 69 which may also be used to electrically connect the bared end of a wire conductor, not shown. The lower horizontal portion 67 is provided with an opening 70 to receive the projection of insert 49, while the portion 67 rests upon the ledge 47 and a pair of extending cars, 221 shown, which are arranged to be received in recesses The removable stationary contact 62 has an inclined portion 71 having a bottom surface which rests upon the inclined surface 45a of the boss 45. The upper surface of the inclined portion 71 preferably is provided with a contact material, such as a noble metal or alloy thereof, which has a high current conducting and are extinguishing capability. The inclined portion 71 is connected to a securing portion 72 by an intermediate portion 73. The intermediate portion 73 is arranged to be received in the recess 46 when the inclined portion 71 is supported on the boss 45. The securing portion 72 has an opening thereon which is arranged to hold captive a screw 74. Extending upwardly and outwardly from the end of the securing portion 72 are a pair of oppositely extending cars '75, which are most clearly shown in FIG. 1. The stationary contact assemblies 61) are installed in each of the ends of the compartments 41-43, as follows. Initially, the Z-shaped terminal connector 61 is inserted into an end of one of the compartments 41-43 so that the underside surface of the upper horizontal portion 63 rests upon the upper surface of the raised portions 50, and the underside surface of the lower horizontal portion 67 rests upon the ledge 47 with the opening 70 receiving the extending portion of the insert 49. The extending ears on the lower horizontal portion 67 additionally aid in maintaining the connector 61 in its inserted position. The removable stationary contact 62 is then installed in position by inserting the same at an angle toward the base 2411 with the ears 75 in contact with the inclined surface 53. The inclined surface 53 directs the contact 62 into position so that the screw 74 is aligned with the opening 70 and the insert 49 while the inclined portion 71 rests upon the boss 45. The removable stationary contact 62 is secured in position when the screw 74 is tightened in insert 49. It will be seen that the foregoing construction provides an arrangement whereby the contact making and breaking portion, which includes the contact material on the Portion 71, may be replaced without disturbing the wire connections which may be secured by the screws 65 and 69 when the device 20 is wired in a control circuit. All that is required to remove the stationary contact portion 62 is to loosen the screw 74 and remove the stationary contact assembly 62 so that a replacement contact assembly 62 may be readily installed as described above.

If desired, an additional switch 80 may be installed in either or both of the compartments 32. In FIG. 6, only one switch 80 is shown as installed in the lower righthand compartment 32, it being understood that an additional switch 80, not shown, may be installed in the upper left-hand compartment 32, as in FIG. 6. The external configuration of switch 80 is most clearly shown in FIGS. 1 and 5 and the position of the switch 80 within the compartments 32 is most clearly shown in FIGS. 6 and 10. As shown in FIG. 6, the compartments 32 are located on opposite corners of the support 24 and are identical in configuration and extend in opposite directions from the centerline 20b. Thus the compartments 32 each will receive an identical switch 80 which, when positioned therein, will extend in opposite directions of the centerline 20b.

The switch 80, as shown in FIG. 6, includes two mating housing parts 81 and 81a which are basically mirror images of each other. The housing parts 81 and 81a are sized so that when the switch 80 is positioned in either of the compartments 32, a front nose portion of the housing parts 81 and 81a will engage the upstanding wall 38 while the rear portions thereof are positioned by the wall 39. The housing parts 81 and 81a are secured to gether by means of a fastening means, such as rivets 82, which extend through aligned openings in the housing parts 81 and 81a, and when secured together provide an internal cavity 82b, shown in FIG. 10, wherein a stationary contact assembly 83, a movable contact assembly 84, and a rotatable actuator 85 are received.

The stationary contact assembly 83 includes a contact button 83a which is secured to one end of a resilient metal support 83b. The other end of the support 83b is secured to a rigid metal member 83c which is provided with a threaded opening to receive a terminal screw 83d which, when tightened, will force a clamp into tight engagement with the bared end of a conductor wire, not shown. The movable contact assembly 84 includes a contact button 84a which is secured to one end of a resilient metal support 84b. The other end of the support 84b is secured to a rigid member 840 which is provided with a threaded opening to receive a terminal screw 84d which, when tightened, will force a clamp into tight engagement with the bared end of a conductor wire, not shown. The rigid members 83c and 84c are shaped as shown to have a portion extending from the cavity 8212 through openings in the housing parts 81 and 81a to the exterior of the switch 80 so the screws 83d and 84d are externally accessible. The areas of securement between the supports 83b and 84b and the respective rigid members 83c and 840 are positioned within recesses which are provided as extensions of cavity 82b and which are sized to tightly receive the areas of securement between the supports 83b and 84b and the rigid members 830 and 84c. Additionally, the rigid members 830 and 840 are provided with suitably located ears which extend outwardly to be respectively received in openings indicated as 81b and 810 in FIG. 5, which are formed in the housing parts 81 and 81a to further position the contact assemblies 83 and 84 in the switch 80. As shown in FIG. 10, the resilient support 8312 has a downwardly curved portion 83g which is arranged to position the contact button 83a in spaced relation to the walls which form the cavity 82b. Similarly, the resilient support 84b has a curved portion 84g located intermediate the contact button 84a and the end portion which is secured to the rigid member 840. The curved portion 84g is downwardly curved as shown and extends toward an opening 81d in the housing parts 81 and 81a. Each of the housing parts 81 and 81a are provided with an opening, which openings are aligned when the housing parts 81 and 81a are secured together to provide pivot bearings for journals 85a which extend in opposite directions on the rotatable actuator 85. The actuator 85 has an actuating arm 85b extending outwardly through the opening 81d to the exterior of the housing parts 81 and 81a. The arm 85!: has oppositely facing rounded surfaces on the top and bottom surfaces of the end which extends exterior to the housing parts 81 and 81a. Located intermediate the journals 85a and the rounded surfaces on the arm 85b are raised portions which position one end of a compression spring 86 which has its other end seated on the bottom surface of the cavity 82b so as to constantly urge the actuator 85 counterclockwise. As shown in FIG. 10, extending outwardly from the journals 85a generally in the opposite direction from the arm 85b is a lever portion 85d which has a substantially fiat surface at its free end. Also extending outwardly from the journals 85a generally at right angles to the lever 85d is a lever 85c. Extending between the levers 85d and 85e is a recess 85].

When the actuator 85 is positioned in the switch 80, as shown in FIG. 10, the contact buttons 83a and 84a of the switch will be in the normally open position; that is, the spring 86 causes the actuator 85 to normally be rotated counterclockwise to a position where the lever 85a! is positioned below the curved portion 84g. When the actuator 85 is caused to be rotated clockwise by an outside force which is impressed on the rounded surface of the actuating arm 85b, as will be hereinafter described, it will be seen that the flat surface on the free end of the lever 85d will ride upon the curved portion 84g to a position where the flat surface of the lever 85d is substantially centered on the apex of the curved portion 84g, causing the contact buttons 84a to move into contact making position with the button 83a. The flattened surface on the lever 85d is arranged so that the vibrations which may be imparted to the actuator 85 will not cause separation of the buttons 83a and 84a.

It will be seen that if the actuator 85 is inverted in the switch housing parts 81 and 81a to a position wherein the lever 85:: extends upwardly, in a view not shown, then the force exerted by the spring 86 which urges the actuator 85 in a counterclockwise direction will cause the lever 85:; to move into engagement with the curved portion 84g to cause the contact buttons 83a and 84a to normally engage one another. When the actuator 85 is rotated clockwise to its actuated position, the recess 85f will be in alignment with the curved portion 84g so the contacts will separate under the action of their resilient supports 83b and 84b. Thus it will be seen that a reversal of the position of the actuator 85 will cause the contact buttons 83a and 84a of the switch 80 to be either in a normally closed or in a normally open position. Further, when the actuator 85 is arranged so the contact buttons 83a and 84a are in the normally open position, when the actuator 85 is rotated, vibration will not cause separation of the contact buttons 83a and 84a to thereby prevent the arcing which normally otherwise would occur because of vibrations imparted to the device.

The housing parts 81 and 81a are substantially identical with the exception that, as shown in FIG. 5, the housing part 81 is provided with an opening 81e which is 75 located so as to be in alignment with the contact buttons 83a and 84a. This opening his permits visual observation of the contact buttons 83a and 34a to determine if they are operative. Additionally, the housing part 81a is provided with a recess at its lower surface which is aligned with the openings which receive the rivets 82. This recess is utilized to provide a seat for a leaf spring member 82a, shown in FIG. 1, which is secured to the housing part 81a by one of the rivets 82 and which is arranged to be received in the vertically extending recess 40 in one of the partitions 29a or 2% facing one of the compartments 32 when the switch Si) is inserted into the compartments 32. The spring 82a resiliently positions the switch 80 in the compartments 32.

As shown in FIG. 10, removably detached and supported by the stationary contact assembly, which includes the support 24, is a magnet and movable contact assembly 90. The movable contact assembly is secured to the support 24 by a pair of screws 91, shown in FIG. 1, which are threaded into the inserts 36 in the support 24. The movable contact assembly 90 includes a housing 92 formed of molded material to provide an internal cavity, which will be later described. The housing 92 is generally rectangular in shape and has bottom and top walls, indicated respectively as 92a and 92b in FIG. 5. Extending from the opposite corners of the housing 92, as in FIGS. 1 and 7, are bosses 920. The top and bottom surfaces of the bosses 920 are spaced below and above the top and the bottom walls 92b and 920, as in FIG. 5, with the spacing between the bottom wall of the bosses 92c arranged so the bottom wall 92a engages the top walls 34 of the support 24 as the bottom wall of the boss 92c rests upon the top surface of the bosses 35. The bosses 920 are each provided with a bore to permit passage of the securing screws 91 which are threaded into the inserts 36 in the support 24. As shown in FIGS, 2 and 3, the side walls of the housing 92 are provided with strengthening ribs, indicated by 9201, with the central ribs at the top of the device, as in FIGS. 2 and 4, being provided with vertical slots 91a for securement of a pilot light to be later described.

As shown in FIGS. 1 and 5, extending downwardly from the bottom wall 92a and spaced to be received in the compartments 41 33 when the housing 92 is positioned on the support 24 in a position to be behind the terminal screws 65 and the clamps 65a are bosses 92c which acts as wire stops to limit the depth of penetration of the wire leads beneath the clamps 65a which are tightened by the screws 65. Also, as shown in FIG. 5, extending downwardly from the bottom wall 921: is a rectangular boss 92 which is sized to extend into the recesses 57 in the partitions 39 and 31 for positioning the housing 92 on the support 24. The bottom wall 92a has a rectangular opening 92k, as in FIG. 7, extending between the side Walls 92g and 9211 which also extends through the boss 92 to effectively divide the boss 92f into a pair of bosses. The centerline 200 of the housing 92 is coplanar with the centerline 29b of the support 24 when the housing 92 is positioned on the support 24. If desired, a pair of spaced downwardly extending guides 92f, one of which is shown in FIG. 5, may be formed to extend downwardly from the bottom wall 92a to present a vertical wall vertically aligned with an edge of the opening 92k. The guides are received in the stepped portions which provide vertical Walls 58 when the housing is positioned on the support 24.

As shown in FIG. 1, the housing 92 has an internal cavity 93 which is rectangular in shape. The cavity is centered on the centerline 200, shown in FIG. 7, which also provides a centerline for the opening 92k in the bottom wall 92a of the housing 92, A bottom wall 93a of the cavity 93 extends generally parallel to the bottom Wall 92a. Extending downwardly from the bottom wall 93a into the bosses 92 on either side of the opening 92k are recesses 93b and 930 which, as shown in FIG. 7, are identical in shape and extend in opposite directions of the opening 92k. Each of the recesses 93b and 930 have a spring seat 93:! on their bottom surfaces. Extending upwardly from the bottom wall 93a and projecting inwardly into the cavity 93 from the opposite side walls of the cavity, as in FIG. 7, are a pair of bosses 93c. As shown in FIG. I, the bosses 93a have a top surface which is coplanar with a bottom edge of a notch 94 in the side walls 92g and 9211 wherein a threaded insert 94b is embedded. As shown in FIG. 7, the bosses 93a are preferably rectangular in shape and have a side wall 93 vertically aligned with an edge of the opening 92k and a wall 93g parallel to the wall 93 spaced from an end wall 9311 of the cavity 93. A partition 93j extending from the bottom wall 93a between walls 93g and end wall 93h provides a recess 93k. A rib extends along opening 92k and around the recesses 93b to add strength to the bottom wall 93a. Extending inwardly from the opposite side walls of the cavity 93 are vertical ribs which extend upwardly from the bottom wall 93a to the top surface 92b and have a side wall 93p in vertical alignment with an edge of the opening 92k. The side walls 93 and 93p are thus parallel and spaced on opposite sides of the opening 92k and form slots or guideways 93x at opposite ends of the opening 92k, which are perpendicular to the bottom wall 92a of the cavity 93 and centered on centerline 20c. The material of the housing 92 surrounding the recess 930 is raised to provide a rectangular boss 93:- which has a length at least equal to the length of a metal plate 940, shown in FIGS. 4 and 7, and a width extending from the opening 92k to a side wall 93s of the cavity 93. The height of the boss 931' is shown in FIG. 4. The boss 931 is provided with a pair of spaced bores which are located to receive screws 95, shown in FIG. 7. Downwardly extending in the boss 931', as shown in FIGS. 4 and 7, is a horizontal recess 93t which extends over the entire length of the boss 93;- and is spaced parallel to the wall 93s. The recess 925i is U-shaped, having a depth equal to its diameter and extends along an axis parallel to the centerline 20c. The wall 93s of the housing 92 is also provided with an opening 93v as shown in FIGS. 1 and 3 which exposes the interior of the cavity 93 to the exterior of housing 92.

The foregoing constitutes a description of the location and shape of both the exterior and interior of the molded housing part 92 of the movable magnet and housing assembly 90.

A movable contact and guide assembly 96 for the device which is carried by the housing part 92 and is most clearly shown in FIG. 9, includes a U-shaped support 96a which is preferably formed of a molded insulating material to have a pair of spaced upwardly extending arms 96b which are interconnected by a bight portion 960. The support 96a is sized to be inserted upwardly through the opening 92k in the bottom wall 92a of the housing 92 with the arms 96b received in the slots 93x which guide the support 96a along a vertical reciprocal path of movement relative to the bottom wall 92a of the housing 92. Extending forwardly at the junction of each of the arms 96b and the bight portion 96c are rectangular sockets 96d which extend outwardly of the bight portion 96c. The sockets 96a each have appreciable depth and face in the same direction which, for descriptive purposes, will be indicated as facing the front of the support 96a, as shown in FIG. 9. If desired, the rear face of the support 96a, as shown in FIG. 7, may be provided with ribs 9de which are received in suitably located slots in the material of the housing 92 which surrounds the opening 92k.

Centrally located in the bight portion 96c is a bore 967 which extends downwardly to a rectangular opening in the rear face of the bight portion 960. As shown in FIG. 4, the bore 96] has its upper end countersunk. The rectangular opening is arranged to receive a nut 202 which threadedly receives a screw 201 which extends through 7 bore 96 As shown in FIG. 9, extending downwardly of the bight portion 96c are three U-shaped movable contact supports 9611 which are spaced from each other by grooves 961'. The grooves 96f and the supports 96h are arranged so that when the assembly 96 is positioned in the housing 92 and the housing 92 is positioned on the support 24, the bight portion 96c will be positioned in the notches 54-56 in a manner so that the supports 9611 will extend downwardly into the compartments 41-43while the grooves 96 straddle the portions of the partions 30 and 31 below the notches 56. The supports 96h are identical and each includes a substantially rectangular opening 96x. As shown in FIG. 4, the openings 96x have a spring seat on one end and a substantially flat wall 96m on its opposite end. A movable contact 96n, a contact retainer 96p and a spring 96r are positioned in each of the openings 96x with the contact 9611 held against the flat wall 961'! by the retainer 96p which is urged into engagement with the contact 96m by the spring 96r. The spring 96r is of the compression type and has one end positioned by the spring seat in the openings 96x and its other end positioned between a pair of spaced bent-up portions 96s extending along opposite edges on the retainer 96p. As shown in FIG. 1, the bent-up portions 96s are provided with centrally located notches 96: and oppositely extending ears 96v, which ears 96v are arranged to engage the front and rear faces of the arms of the U-shaped supports 96h surrounding the opening 96x so as to maintain the retainer 96p in the opening 96x. Spaced between the bent-up portions 96s, the retainer 96p has a raised conical boss 96w which acts as a seat for the spring 961'. The movable contact 9511 has a central portion 96y and portions 96z which extend in opposite directions from the central portion 96y at an inclined angle which is identical to the angle of incline of the portions 71 of the stationary contacts 62. Each of the portions 96z are provided with a surface of contact material which has a high current carrying and are suppressant capability which is engageable with the contact material of the removable stationary contact 62 when the assembly 96 is positioned relative to the support 24, as in FIG. 4. The central portion 96y is provided with a raised, centrally located, conical boss similar to boss 96w, which is received within the conical recess formed in the material of the retainer 96p opposite the conical boss 96w, The conical recess in the retainer 96p and conical boss on the portion 96yserve to maintain the central portion 96y in engagement with the flat wall 96m. Located as shown in FIG. 1, along opposite edges of the central portion 96y, are-bent-up ears 96 which are spaced and formed to extend upwardly from the central portion 96w andarranged to be received in the notches 96t on opposite sides of the retainer 96p to prevent movement of the movable contacts 96n in a direction transverse to the supports 96h.

During assembly, a movable contact96n is inserted in position beneath the contact retainer 96p byImerely manually raising the retainer 96p against the force of the spring 9dr and inserting-the movable contact 96n into a position wherein the central portion 96y is aligned with the flat wall 96m of the opening 96x. The retainer 96p when released is urged by the spring 9dr into tight engagement with the movable contact 96n so that the conical recess of the retainer engages the conical boss on'the central portion 96y of the movable contact 96!! and the ears 96w are received in the notches 96t of the retainer 96p to thus maintain the movable contact 9611 in position. It is to be appreciated that the foregoing arrangement will permit the movable contact 96m to move vertically upwardly in the opening 96x but will prevent a transverse separation of the movable contact 9612 and retainer 96p because of the ears 96a which are received in the notches 96t act as a ratchet when the movable "contacts 9611 are inserted into position beneath the rethe lower ends of each of the arms 96b are ledges 97. The ledges 97 extending over the entire width of arms 96b are arranged to be received in the notches 54 of the support 24, so as to provide portions which extend in opposite directions of the centerline 201;. As shown in FIG. 10, extending downwardly below each of the ledges 97 are projections 98 which are respectively formed on opposite sides of a centerline 99 of the support 96a. The projections 98 have a side wall 98a located on the centerline 99 and have a flat bottom surface 98b. As shown in FIG. 9, the projections 98 are each spaced from the support 96h adjacent thereto by a groove 980 which is adapted to straddle the portion of walls 29a and 2912 below the bases 55a of the notches 55. The foregoing completes a description of the movable contact and guide assembly 96.

A bell crank type actuator assembly, which is most clearly shown in FIG. 9 and is rotatably positioned in the housing 92, is formed of molded insulating material to have a pair of spaced pivot portions 101 which extend downward from a solid lever portion 102. Extending outwardly from each of the pivot portions 101 on opposite ends of the lever portion 102 are a pair of spaced levers 103 each of which has a ball 104 integrally formed on its free end. The pivot portions 101 each are provided with a bore 105 which are in axial alignment with one another and which act as a bearing for a metallic rod 106. Extending outwardly of the bores 105 on the pivot portions 101 are bosses 107 which are sized to engage the internal walls of the cavity 93 and axially position the actuator 100 in the cavity 93 in the housing 92, as in FIG. 7. Also, it will be seen in FIG. 7, that when the actuator is positioned in the cavity 93, a clearance is provided between the levers 103 and the ribs 9311. As shown in FIG. 9, spaced between the pivot portions 101 of the lever portion 102 along an end 113 which is remote from the pivot portions 101, is a modified ball portion 108 of a ball and socket combination. As shown in FIG. 4, the ball portion 108 includes a vertical planar surface facing in the same direction as the levers 103 and define one side of a recess 109. The-ball portion further includes a raised elongated lentil-shaped portion 110 which is substantially plano-convex in cross section along both a transverse and longitudinal axis.

Positioned on each of the balls 104 and on the ball portion 108 is an insert which is preferably formed of a relatively resilient molded. plastic material. As shown in FIG. 9, the inserts which are positioned on balls 104 are U-shaped channel-like members 111 having a rectangular outer shape sized to be loosely received in the sockets 96d and a spherical indentation formed on the inner surfaces of each of the arms of the channel-like inserts 111 which indentation is sized to correspond to the outer curvature of the balls 104.

The insert member 112 which is positioned on the ball portion 108 consists of a U-shaped channel-like memher having appreciable length. One arm of the member 112 is sized to be received in recess 109 and the other arm has a recess formed on its inner surface which is complementary in shape to the shape of the plane-convex shape of the lentil-shaped portion 110. The inner surface of the bight of the member 112 is curved to correspond with the curvature of the free end 113 of lever 102, and a pair of ears 114 are provided on the free ends of the bight portion of member 112 which rest upon the upper surface of the free end 113 to further position the member 112 on lever 102. It will be seen that while the members 111 and 112 provide a ball and socket connection to each of the levers 103 and 102, the relatively large outer surfaces of the channel-like members 111 and 112 provide an appreciable surface area for a sliding contact with other moving members.

The components of the electromagnet assembly 115 for the device 20, which are most clearly shown in FIGS. 5 and 8, include an E-shaped stationary magnet core assembly 116, a movable T-shaped armature assembly 117 and a magnet coil assembly 118. As shown in FIGS. 1 and 8, the magnet core assembly 116 comprises a stack of laminated magnetic metal parts which are secured together by rivets 119 to provide a magnet core 120. The magnet core 120 has a base portion 121 from which extends a pair of spaced parallel arms 122 and a leg 123 spaced intermediate the arms 122. The arms 122 each have a pole surface 134 on a free end which is located beyond a surface 137 of the leg 123. The surfaces 134 each have a groove formed therein to position a closed conductor loop which acts as a shading coil for the magnet structure. Each of the arms 122 have an outwardly extending lug 129 formed thereon which lugs 129 provide a surface 130 which is spaced from a surface 124 of the base portion 121.

As shown in FIGS. 5 and 8, the armature assembly 117 comprises a stack of laminated magnetic metal parts 131 which are secured between a pair of metal platelike members 132 and 133 by rivets 134a. The laminated parts 131 have portions which extend beyond the boundary of the metal parts 132 and 133 to provide pole faces 135 for the armature assembly 117 which are aligned with the pole surfaces 134 of the magnet core assembly 116. Extending between the surfaces 135 on the parts 131 and the members 132 and 133 is a central leg portion 136. The leg portion 136 on parts 131 extends beyond the boundaries of the members 132 and 133 to provide a face 138 which is arranged to be slightly spaced from the surface 137 on leg 123, when the faces 135 engage the surfaces 134. The member 132 is generally T-shaped to correspond to the T-shape of the parts 131 and has an exposed flat surface 139, shown in FIG. 5. As shown in FIG. 8, the member 133 has a rectangular central portion 140 secured to parts 131 and a portion 141 secured to the leg portion 136. Extending upwardly on the portion 140, as shown in FIGS. 1 and 5, are portions 142 which are formed to extend perpendicular to an exterior surface 143 of the member 133 at the opposite ends of the portion 140.

Extending downwardly along an edge 144 of the portion 140 and opposite to the portions 142 is a lever 145. As shown in FIG. 5, the lever portion 145 extends perpendicular to the surface 143 in a direction opposite to portions 142 and is arranged to provide a surface 146, which is spaced from the parts 131.

The magnet coil assembly 118, which is most clearly shown in FIG. 1, comprises a molded plastic housing or case, which is formed to have a rectangular base 147. The base 147 has a top surface 148, a bottom surface 149, a front wall 150, a rear wall 151 and a pair of spaced side walls 152. Extending along the edges between each of the side walls 152 and the top surface 148 is a rectangular groove 153 having a bottom surface coplanar with a top surface of a rectangular ear 154, each of which extends outwardly of one of the side walls 152 and has a surface forming an extension of the rear wall 151. The ears 154 have a depth and width equal to the depth and width of the notches 94 in the housing 92 and are received therein when the magnet assembly is positioned in the cavity 93. The base 147 is sized so a portion of the bottom wall 149 rests upon a top edge of the housing 92 adjacent the opening 93v when the ears 154 are positioned in the notches 94. A plurality of recesses 155 which are separated by upstanding ribs 156 are formed in the top surface 148 along the edge between the top surface 148 and the front wall 150. Embedded in the bottom surfaces of each of the recesses 155 is a threaded conductor, not shown, which threadedly receives a screw 157 which is arranged to tighten a wire clamp against a bared end of a wire conductor, not shown. Extending downwardly from the bottom surface 149 is a U-shaped housing 159 for the windings of a magnet coil which is embedded in the molded. material of the housing 159 and extends into a portion of the base 147. The wire 16 winding of the coil is connected by suitable leads embedded in the molded material of the base 147 and which extend to the embedded inserts which receive screws 157. The housing 159 has an end 169 coplanar with the rear wall 151 and an end 161 spaced rearwardly of the front wall 150 so as to expose a considerable portion of the bottom surface 149 between end 161 and the front wall 150. As shown in FIG. 8A, the housing 159 has a rectangular opening 162 extending between the ends and 161 which has a top wall 163, a bottom wall 164 and a pair of side walls 165. Extending outwardly from the end 161 is a boss 166, most clearly seen in FIG. 1, which has a surface 167 coplanar with the bottom wall 164. Extending downwardly from the top wall 163 and upwardly from the bottom wall 164 from the end 160 approximately half the distance to the end 161 are raised portions 168. These raised portions 168 are arranged tov loosely center the leg 123 of the magnet core 120 in the opening 162.

A member 126, formed of resilient metal, has an end 125 in clamping engagement with the top surface 148 and a portion extending between raised portions 168 in engagement with the center leg 123 to resiliently position the magnet core 120 on the base 147. Extending outwardly of the end 125 is an arm which extends along the bottom surface 149 to a curved end 128. The end 128 extends perpendicular to the surface 149 in spaced relation to the front wall 150. Extending between the rear wall 151 and the front wall 156 in the bottom surface 149 of the base 147 is a groove 169 which is arranged to receive the arm portion of the metal member 126. Also formed in the bottom wall 164 and the surface 167 and the top wall,

163 are grooves 170 which provide clearance for the rivets 134a, when the core assembly 116 and the armature assembly 117 are assembled with the magnet coil assembly 118, as will now be explained.

The assembly of the components of the electromagnet assembly 115 is readily accomplished by positioning the member 126 on the base 147, as above described, and inserting the leg 123 of the magnet core 120 into the opening 162 into a position wherein the base portion 121 rests against the end 160 of the housing 159. When the magnet core 126 is thus positioned, the arms 122 will extend exterior of the housing 159 so that the free end surfaces 134 will be positioned forwardly of the end surface 161, and the leg portion 123 will be positioned by the raised portions 168 which terminate to the rear of the free end surface 137 of the leg portion 123. The free end surface 137 will be positioned in the opening 162 to the rear of the surface 161. When the magnet core 120 is thus positioned it will be seen in FIG. 1 that the curved end portion 128 of the metal member 126 is positioned forwardly of the front surface 150. The T-shaped armature assembly 117 is installed in position by inserting the leg portion 136 into the opening 162 with the portions 142 extending alongside the side walls 152. The armature assembly 117 is moved to its final assembled position when a slight force is exerted to cause the curved end 128 to be forced out of a position to permit the lever 145 to pass the curved end 128.

When the armature assembly 117 is thus positioned, its movement relative to the coil assembly 118 will be guided by the portions 142 which are engageable with the side walls 152, and the hard surfaces of the members 132 and 133 which engage the surface 149 of the base 147 and the surface 167 of the boss 166. The extent of the movement of the armature assembly 117 in one direction will be limited by the inside wall of the housing 92. Move ment of the armature assembly 117 in the other direction is limited by the engagement between the surfaces of the faces 135 and 134 on the core 120 and the armature assembly 117.

A cover forthe housing 92, which is most clearly seen in FIGS. 1 and 5, is formed as a molded plastic part to have a top surface 176, a bottom surface 177, a rearwall 178, a front wall 179 and side walls 180 and 181. The walls 178, 179, 180 and 181 are sized so the cover 175 forms a continuation of the outer walls of the housing 92. The bottom surface 177 is provided with a recess, not shown, which receives the top surface 148 of the coil assembly 118 While portions of the cover 175 adjacent the recess rest in grooves 153. Extending downwardly from the bottom surface 177 are a pair of rectangular lugs 182 which are located adjacent the corners of the front wall 179 and the side walls 180 and 181. The lugs 182 are arranged to engage portions of the inner walls of the housing 92 for positioning the front wall 179 portion of the cover 175 on the housing 92 in a direction of movement along an axis perpendicular to the walls 180 and 181. Also extending downwardly from the bottom surface 177 are a pair of lugs 183 which are disposed proximate the corners defined by the rear wall 178 and the side walls 180 and 181. As shown in FIG. 5, the lugs 183 each have a vertical wall 184 which is arranged to engage an inner Wall portion of the housing 92 so as to position the cover 175 on the housing 92 along an axis perpendicular to the rear wall 17 8. The lugs 183 also have an inclined wall 185 which faces downwardly of the bottom surface 177 and toward the front wall 179. The inclined surface 185 is arranged to be received in the recesses 93k in the housing 92, for a purpose to be later explained.

Again referring to FIG. 1, the top surface 176 is provided with a pair of recesses 186 which extend into the side walls 180 and 181. The recesses 186 are each provided with an opening aligned with openings in the ears 154 of the magnet coil assembly 118 and the inserts 94b in the housing 92 so that screws 187, when threaded into inserts 94b, will secure the cover 175, the magnet assembly 118 and the housing 92 together. The front wall 179 of the cover 175 is provided with a central recess which has a wall 188 spaced to the rear of the recesses 155 and the ribs 156. This arrangement-Will provide a suitable protected area whereon information of the coil characteristics of the device may be marked and an indication of the markings for the terminals which include the screws 157 may be applied. It will be seen that the recess which provides the wall 188 effectively causes the cover 175 to have a pair of ears indicated by numerals 189 and 190 which respectively have one edge formed by the side walls 181 and 180 and another edge formed by the front wall 179. The ears 189 and 190 are respectively provided with openings 193 and 194 which extend parallel to the front wall 179 for positioning a start-stop push button switch, as will be later explained. The opening 194 is formed in cover 175 to be in alignment with the portions 142 on the armature assembly 117, so as to visually expose a portion of the portions 142 when the armature assembly 117 is in a deenergized position. The car 190 is provided with an additional opening 195 which extends through the ear 190 so as to visually expose the portion 142 when the armature assembly 117 is in its energized position. Thus the openings 194 and 195 provide an arrangement which will permit observation of the device to determine if the device 20 is in an energized or de-energized condition. If desired, the wall portions which form openings 194 and 195 may be inclined so suitable markings, such as OFF and ON, may be included thereon. Further, if desired, the openings 194 and 195 may be interconnected by an opening 196, which may be used to permit passage of a suitable instrument, not shown, which may be inserted between the surfaces 134 on the magnet core assembly 116 and surfaces 135 on the armature assembly 117 to maintain the armature assembly 117 against movement during shipment of the device 20. Additionally, the opening 196 may be used to permit passage of an instrument to a position between the armature assembly 117 and an inner wall portion of the housing 92 to maintain the armature assembly 117 in an energized position when it is desirable to check the circuits wherein the device 20 may be wired without energizing the magnet coil assembly 118 of the device.

It is believed a description of the assembly of the switch assembly will aid to the further understanding of the features thereof. As previously set forth, the stationary contact support 24 is initially secured to the mounting plate 21 by the screws 26 and the assemblies 60 are installed at the opposite ends of compartments 41-43. As shown in FIG. 4, the installation of assemblies 60, shown in FIG. 6, in the compartments 41-43 of the support 24 is accomplished by first installing the terminal connectors 61 in position and then positioning the removable contacts 62 of the contact assemblies 60 so the screws '74 may be threaded into the inserts 49.

If desired, as shown in FIG. 1, one or two electrical switches may be included in compartment 32. The foregoing completes the assembly of the stationary contact assembly which is carried by the stationary contact support 24.

The assembly of the movable contact assembly 96, which is carried by the housing 92, is preferably initiated by positioning the movable contacts 96n beneath the contact retainers 96p which are biased by springs 96; in each of the openings 96x of the support 96a, so as to complete the assembly of the movable contact and guide assembly 96, which is most clearly shown in FIG. 4. If desired, a metal liner 197, shown in FIG. 1, may be inserted in each of the guideways 93x. The movable contact and guide assembly 96 is then positioned in the housing 92 by insetting the arm portions 96b upwardly through the opening 92k so the arm portions 96b are slideably received by the liners 197 in the guideways 93x. The liners 197 are included to minimize wear of the parts as the movable contact and guide assembly 96 reciprocates in the housing 92. Proper orientation of the movable contact and guide assembly 96 in the housing 92 is achieved by the ribs 962 which permit the movable contact and guide assembly 96 to be inserted through the opening 92k only when the ribs 96e are properly aligned with the openings in the side wall of the opening 92k. After the movable contact and guide assembly 96 is thus positioned in the housing 92, a return spring assembly 198, shown in FIG. 4, consisting of a pair of springs 199, a spring seat 200, the screw 201 and the nut 202, as shown inFIG. 4, is installed in the housing 92. The installation of the return spring assembly is accomplished by positioning the nut 202 in a recess in the bight position 96c, which is aligned with the bore 96 and positioning the springs 199 in the recesses 93b and 930. The spring seat 200 has a pair of raised bosses which act as seats for'springs 199 at its opposite ends and an opening centrally located therein which is arranged to permit the screw 201 to pass therethrough and through the bore 96f into threaded engagement with nut 202. The return spring assembly 198 constantly biases the bight portion 960 toward the bottom wall 92a of housing 92.

The bell crank actuator assembly 100, which includes the metallic rod 106, the inserts 111 on balls 104, and the insert 112 on the lentil-shaped portion 110, is then positioned in the cavity 93 of housing 92. The insertion of the actuator assembly 100 is accomplished by positioning the inserts 111 in the sockets 96d and permitting the pivot portions 101 to move to a position so the rod 106 is positioned in the horizontal recess 93t. The bell crank actuator assembly 100 is maintained in position in the cavity 93 of the housing 92 by the metal plate 940 and the pair of screws 95. The metal plate 940 has a portion resting on the rod 106, as shown in FIG. 4, and is secured in position on the boss 93; by the screws 95 which pass through suitable openings in the plate 94c and the bosses 931' to the outer bottom wall 92a where they threadedly receive nuts, not shown. The assembly of the movable contact portion of the magnet and movable contact assembly is completed when a pair of leaf-like spring members 205, shown in FIGS. 1, 4, 7, and 10, are installed in the cavities 93k. The spring members 205, as shown in FIG. 10, have a U-shaped bottom portion arranged so an arm portion 206 is pressed into engagement with the wall 93g and another arm portion 207 is pressed into engagement with the wall 93h and extends from the bottom of cavity 93k to the top edge wall of the wall 93/1. The free end 208 of the arm portion 207 is curved away from the wall 9311, as shown in FIG. 10.

The assembly of the components of the electromagnet assembly 115 has been previously set forth so that, as shown in FIG. 5, the components comprising the stationary contact support 24, the movable contact assembly and parts associated with housing 92, the electromagnet assembly 115 and the cover 175 are conditioned for assembly with one another.

If desired, the assembly which includes the housing 92 may be first positioned on the stationary contact support 24 and secured thereto by the screws 91 which are threaded into the inserts 36. The assembly of the housing 92 and the support 24 will align the movable contacts 96m in a position relative to the stationary contact assemblies 60 so the portions 961 of the movable contacts 9611 will engage the portions 71 of the stationary contacts when the movable contact and guide assembly 96 is moved toward the base 24a against the force of the springs 199.

After the foregoing assembly has been completed, the previously assembled electromagnet assembly 115 is installed in position in housing 92. This is accomplished by inserting the elecrtomagnet assembly 115 in a position wherein the lever portion 145 hooks over the channellike insert 112 and the ears 154 are received in the notches 94. When the electromagnet assembly 115 is thus positioned, the lugs 129 will be positioned in the cavities 93k with the surfaces 130 facing the arm portions 207 of the springs 205 and the terminal portion of the coil which includes the screws 157 will be exposed at the upper surface of the assembly thus far completed.

The assembly of the basic switch assembly 20 is completed when the cover 175 is applied to the top surface of the housing 92. The cover 175 is positioned to have recesses 186 in alignment with the openings in cars 154 of the electromagnetic assembly 115 and the threaded insents 94b. The screws 87 are then threaded into the inserts 9411. During the tightening of the screws 187 into the inserts 94b, the inclined wall 185 on the lugs 18 3, see FIG. 5, engages the curved free end portion 208 of the springs members 205 to thereby force the arms por tions 20 7 to the night, see FIG. 10. As shown in FIG. 1, when the arm portions 207 move to the right they engage the surfaces 130 on the lugs 129 of the stationary magnet assembly 116 to resiliently position the electromagnet assembly 1 in the housing 92, and provide a media for absorbing shock when the coil assembly 118 is energized to cause the armature assembly 1 17 to move into engagement with the stationary magnet assembly 116.

From the foregoing it is apparent that the switching assembly can be readily serviced without disturbing the wire connections to the terminal screws 65-. If the coil is believed to be faulty, all that is required is that the leads to coil terminals be removed by loosening the screws 157, and the cover 175 and electromagnet assembly 115 may be removed from the housing 92 by loosening the screws 187. When this operation has been performed, an entirely new replacement electromagnet assembly 115 may be installed in a manner previously described or the coil assembly 1 18 may be removed from its cooperating position with the. stationary magnet assembly 1 16 and the armature assembly 117. This later operation is performed by manually pulling the armature assembly 117 and the stationary magnet assembly 116 in opposite directions to force the curved end portion 128 of the spring metal member 126 to an out'-of-the-way position whereby the armature assembly 1 17 and magnet assembly 116 may be readily disassociated from the coil assembly 18. The reassembly of the armature assembly 117, the stationa y magnet assembly 116 and the replacement coil assembly 118 is accomplished in the manner previously described. Thus the coil assembly 1*18, the armature assembly 1'17 and the stationary magnet assembly 116 may be serviced and inspected without disturbing the stationary and movable contact assembly portions of the switching assembly 20.

If it is desired to inspect or replace the movable contacts 96n or the stationary contacts 62, all that is required is that screws 91 be loosened, so the housing 92, the electromagnet assembly 115 and the cover 175 may be removed as an assembled unit from the stationary contact support 24. It is apparent that this operation can also be performed without disturbing the connections of the wires which are secured by the screws 65. When the housing 92 is detached from the support 24, the movable contacts 96m and the stationary contacts 62 may be readily inspected and replaced, as precedingly described.

In view of the foregoing, the operation of the switching assembly 20 is as follows. When the coil assembly 118 is deenergized, the springs 199 will constantly urge the movable contact and guide assembly 96 upwardly lirom the base 24a so the contacts 9622 are separated 'from the stationary contacts 62. The upward movement of the guide assembly 9 6 causes the bell crank actuator 100 to rotate about its pivot portions 101 to a position shown in FIG. 4, wherein the insert 112 which is carried by the lentil-shaped portion causes the armature assembly 117 to be moved by its hooked lever portion 145, so as to move the armature assembly '117 to a position wherein the pole faces are separated from the pole faces 134 on the stationary magnet assembly 116. The position of the armature assembly 117 may be readily observed through the openings 194 and 195 in the cover 175 and through the opening 93v in the housing 92. The movement of the armature assembly 117 and the movable contact and guide assembly 96 to their deenergized posit-ions is limited by the hooked lever portion which engages the walls of the cavity '93 surrounding the opening 93v.

When the magnet coil assembly 118 is energized from a suitable source of current, not shown, the magnetic flux induced by the coil assembly 118 in the stationary magnet assembly 116- and the armature assembly 117 causes the armature assembly 117 to move in a direction parallel to the plate 21 to a position wherein the surfiaces 13 5 engage the surfaces 134. The shock attending the engagement of the armature assembly 117 and the stationary magnet core assembly 116 is absorbed by the springs 205. The movement of the armature assembly 117 to its energizcd position is guided by portions of the molded coil assembly 118, as for example, the ears 142 engage the side walls 152, and the portions of the metal plate mem bers 132 and 133 engage the top wall 163 and the bottom wall 164 of the opening 162 while the grooves in the molded coil assembly 118 provide clearance for the rivets 134a which secure the assembly of the parts forming the armature assembly 117.

The molded insert 112 is received between the lever 14 5 and the laminated magnetic metal plates 131 of the: armature assembly 117. Therefore, as the armature as sembly 117 moves to its energized position, the insert 112 is similarly moved. The insert 112 has a generally rec-- tangular outer surface so a nonrota-table connection exists: between the insert 112 and the armature assembly 117.. The insert 112 is centrally positioned on the free end 113 of lever 102 on a lentil-shaped portion 110 by a similarly shaped socket on the inner faces of the channel-like inset 1 12. Thus a connection which will be capable of a limited universal type movement exists between the insert 112 and the lever 102 so the movement of the insert 112 is imparted with a minimum of friction to the lever portion 102 of the bell crank actuator 100. The bell crank actuator 100 is pivoted at its opposite ends on the metallic rod 106 which, as shown in the drawings, extends the entire length of the solid lever portion 102 along an 

9. A SWITCH ASSEMBLY COMPRISING: A BASE HAVING A PLURALITY OF SPACED COMPARTMENTS EACH HAVING A PAIR OF SPACED STATIONARY CONTACTS MOUNTED THEREON, A HOUSING DETACHABLY MOUNTED ON THE BASE; A MOVABLE U-SHAPED CONTACT GUIDE AND SUPPORT HAVING A PAIR OF SPACED ARMS ENGAGING A PAIR OF SPACED SIDE WALLS OF THE HOUSING FOR GUIDING THE MOVEMENT OF THE U-SHAPED CONTACT GUIDE AND SUPPORT ALONG AN AXIS PERPENDICULAR TO THE BASE AND HAVING A PORTION INTEGRALLY FORMED WITH THE SPACED ARMS CARRYING A PLURALITY OF SPACED MOVABLE CONTACTS EACH OF WHICH IS POSITIONED TO BRIDGE ONE OF THE PAIRS OF STATIONARY CONTACTS; A MAGNET ASSEMBLY HAVING AN ARMATURE MOVABLE IN A LINEAR PATH ALONG AN AXIS PARALLEL TO THE BASE; AND A BELL 